Apparatus comprising electronic and/or optoelectronic circuitry and method for realizing said circuitry

ABSTRACT

An apparatus/method for producing fabric-like electronic circuit patterns created by methodically joining electronic elements using textile fabrication-like methods in a predetermined arrangement.

This application is the national phase under 35 U.S.C. § 371 of PCTInternational Application No. PCT/NO00/00137 which has an Internationalfiling date of Apr. 27, 2000, which designated the United States ofAmerica.

The present invention concerns an apparatus comprising electronic and/oroptoelectronic circuitry for implementing electronic and/or opticalfunctions, wherein the circuitry is realized and/or integrated in two ormore dimensions and a method for method for realizing and/or integratingcircuitry in two- or more dimensions, wherein the circuitry compriseselements in the form of wires, fibres, ribbons, strips or multicomponentfilaments and/or combinations thereof, wherein said circuitry iselectronic and/or optoelectronic circuitry for implementing electronicand/or optical functions in an apparatus comprising circuitry of thiskind.

In particular, the present invention concerns integrating filament-likeelectrical and/or optical conduits into two- and three-dimensionalphysical structures for creating electronic or optoelectronic circuitry,sensors and/or emitters. The spatial extent or region of influence ofsuch circuitry, sensors and/or emitters is controlled by specificdefinition of the electrical and/or optical properties of the individualfilaments and how they are incorporated into the structures.

The development of integrated circuits on silicon and semiconductorcompound materials has revolutionized the electronic industry. However,the ever increasing complexity and costs of higher integrationtechnology has generated interest in novel materials and methods.

For instance, progress in conductive polymers and organic materials hasled to novel displays, diodes and field-effect transistors using thesematerials. See G. Horowitz “Organic field effect transistors” Adv. Mat.Vol. 10, pp. 365-377 (1998); D. Pede & al. “A general-purposeconjugated-polymer device array for imaging” Adv. Mat. Vol 10, pp.233-237.(1998); R. H. Friend et al. “Electroluminescence in Conjugated“Polymers”, Nature 397, pp.121-128 (1999).

Thin-film-based inorganic semiconductor technologies compatible with lowtemperature-resistant packaging and substrate materials are under rapiddevelopment, and include amorphous silicon as well as polysilicon andmicrocrystalline silicon. In this connection, see, e.g. J. G. Blake &al., “Low-temperature polysilicon reshapes FPD production”, Solid StateTechnology, pp.151-161 (May 1997).

Defect tolerant architectures have been proposed to circumvent theproblems of trying to produce defect free chips, for instance by J. R.Heath & al ., “A defect-tolerant computer architecture: opportunitiesfor nanotechnology”, Science, Vol. 280, pp. 1716-1721 (Jun. 12, 1998).

Such novel materials and methods open up entirely new opportunities inelectronics and optoelectronics that extend much beyond providing anevolutionary route to alleviating problems and limitations adhering tothe present state of the art. Unfortunately, present-daysemiconductor-oriented technologies are totally inadequate forexploiting the true potential of these novel materials and methods, andthere exist pressing needs for complementing technologies. One area ofparticular importance is that of gaining freedom from the dominatingrole of the substrate.

In traditional silicon-based technologies, the electronic functionalityis derived from the semiconducting silicon substrate, which severelyrestricts opportunities for extensions into the third dimension.Furthermore, physical dimensions are restricted, and the traditionallithographic processes provide only limited flexibility with respect tointra-device connectivity. This includes both the physicalcharacteristics of the connecting lines themselves and how they can bepositioned throughout the device structures in question. Typically, thesubstrate and its layered superstructurescontain electricalinterconnects where electric currents flow in patterned strip- orribbon-like conducting paths that have been created by subtractive oradditive processes.

Subtractive processes are well-known and much used in the semiconductorindustry, and involve wet or dry etching whereby conducting material isremoved from portions of the substrate. Conducting material is retainedin regions where a protective layer has been applied in the patternsdesired, e.g. by optical lithography. Typically, all modernmicroelectronic circuits involve multiple step lithography processeswhere image(s) of parts or all of the circuitry, mostly wires, anddevices are transferred to the substrate. This requires careful registerbetween each step, the more so as the features become smaller andsmaller. The substrate must be extremely flat and rigid. Furthermore,the circuitry cannot be continuous through this approach. Several chipshave to be made individually on one wafer at the time.

Furthermore, the integration of electronic and optoelectronic circuitsis extremely difficult by such methods. It would therefore be highlyadvantageous to find microcircuit fabrication methods which eliminatelithographic processes altogether and allow for flexible continuousfabrication of electronic and optoelectronic circuits.

Additive processes have hitherto been less used in electronic circuits,but may become important in the future. They include microprinting andmicromolding of conducting inks or solid state conductors, screenprinting and more exotic means such as laser mediated deposition (see,e.g. H. Yabe & al., “Direct writing of conductive aluminum line onaluminum nitride ceramics by transversely excited atmospheric CO2laser”, APL 71 2758 (1997)).

The present invention introduces the concept of woven electronics as anew generic approach to making and assembling electronic andoptoelectronic devices and apparatus, in particular by exploitingopportunities that arise with the advent of novel electronic materials.This implies a radical departure from present state of the art. Indeed,literature searches have been performed without being able to identifyany relevant prior art. For the sake of completeness, however, thosepatent documents that were retrieved by the search profiles employedshall be listed here:

-   A) DE 31 16 348 A1. “Elektrische Verbindungseinrichtung”; inventor    Oscar Alonso, USA.-   B) JP 05299533. “Electronic part mounting board and electronic part    device using the same”; inventor Ohigata Naoharu, Japan.-   C) WO96/38025 A1. “Composite materials”; inventor George William    Morris, Great Britain.

Publications A and C describe substrates which incorporate woven layerswith electrical conduits. The latter are, however, applied after theweaving process has been finished, by etching, printing or electronsputtering.

Publication B describes a woven structure incorporating conducting wiresinterspersed with electrically insulating filaments. However, focus ison providing alternative substrates to replace circuit mounting boardssubjected to thermal and mechanical stress, which does not represent anyprincipally new functionality or apparatus impinging on the presentinvention.

Conducting metallic wires are known to be incorporated by weaving into awide range of objects. This includes meshes to act for instance asscreens in houses, and electrodes and filters in material science.Metallic fabrics and metallic embroidery are used to make decorative andprotective clothes. Conducting wires are also integrated into fabrics toprovide clothing and furniture free of electrostatic build-up oralternatively to provide electrical heating. In so-called “smartclothes”, electronic devices and sensors are attached to the clothes andapparels. See S.E. Braddock and M. O'Mahony, “TechnoTextiles-Revolutionary Fabrics for Fashion and Design”, chap. 2, Thames& Hudson, New York 1998. Such applications are outside the scope of thepresent invention, however.

To conclude, in order to realize the potential in a wide range ofemerging electronic and optoelectronic materials and methods, there is aneed for complementing technologies which are not within the present-daystate of the art. Prominent among such technologies are those that canprovide electrical and optical interconnections in two and threedimensions, with high spatial density, high signal speed potential andsmall crosstalk. Also prominent are technologies and materials suitableas structural platforms for large area electronics and/or threedimensional device architectures.

A primary object of the present invention is to provide alithography-free process to produce electronic and optoelectronicdevices, apparatus and circuits in sheet-like or fabric form, or inthree dimensional structures.

It is a further object of this invention to provide for continuouscircuits over large areas and in mechanically flexible final productswhich can be shaped to a desired environment or form factor.

It is still a further object of the present invention to provide intra-and inter-device electrical and optical connections that can carryhigh-speed signals with very low crosstalk.

Another object of the invention is to provide methods to integrateelectronic and optical circuits in a continuous matrix.

Yet another object of the invention is to create functional devices byweaving, knitting, crocheting, knotting, stitching and/or combinationsthereof.

The above objects and advantages are according to the invention realizedwith an apparatus which is characterized in that the circuitry compriseselements in the form of wires, fibres, ribbons, strips, ormulticomponent filaments and/or combinations thereof, said elementsinterfacing in a predetermined pattern such that said circuitry arerealized with intersections in physical or near physical contact betweenthe elements thereof, that said predetermined pattern is generated byintegrating physically two or more of said elements in a fabric-likestructure by any of the following processes, viz. weaving, knitting,crocheting, knotting, stitching and/or combinations thereof, that saidelements include transparent, non-transparent. conducting,semiconducting or isolating materials and/or combinations thereof, thatat least some of said elements according to their material propertiesform electrical or optical transmission lines or isolators in saidcircuitry, said electrical or optical transmission lines conveyingrespectively electrical or optical energy between points and/or areas insaid fabric-like structure, that at least some of said elements comprisespatially defined extended active regions, and that at least some ofsaid elements in portions of said fabric-like structure are adapted foremitting or absorbing electrical, chemical, mechanical or optical energyor by interacting with each other by an exchange of energy of theaforementioned kinds; and a method which is characterized by joining twoor more elements into a fabric-like structure by any of the followingprocesses viz. weaving, knitting, crocheting, knotting, stitching and/orcombinations thereof, such that the elements interfaces in apredetermined pattern, whereby the circuitry is realized with theelements intersecting in physical or near-physical contact in thefabric-like structure, said elements being made of transparent,non-transparent conducting, semiconducting or isolating materials and/orcombinations thereof.

In an advantageous embodiment of the apparatus according to theinvention, the elements are provided in the predetermined patternforming a substantially two-dimensional fabric-like structure, while inanother advantageous embodiment of the apparatus according to theinvention the elements are provided in the predetermined pattern forminga substantially three-dimensional fabric-like structure. In the latterembodiment the elements then preferably each are provided in a spatialdistribution such that the position of the end-points of the elements inthe fabric-like structure defines a spatial pattern or grid.

In advantageous embodiments of the apparatus according to the inventionit is preferred that some of the transmission lines respectively aretwisted pairs, coaxial cables, strip lines or optical fibres.

In the apparatus according to the invention it is advantageous that theactive regions of the elements are defined by exposing portions of thesaid elements to the exterior surroundings thereof. Preferably are thenthe active regions of an element lengthwise extended therein or anactive region of an element corresponds to an end-point thereof.

In the apparatus according to the invention it is advantageous that someof the elements are provided with a protective shielding or cladding,the active regions in these elements being provided by removing theshielding or cladding at selected portions thereof, or alternatively theactive regions of the elements are provided in selected portions of theelements exposed in the surface of the fabric-like structure orprotruding therefrom at selected locations thereof.

According to the invention are preferably the active regions of theelements defined by exposing portions thereof to spatially selectivephysical or chemical influences. In the latter case it is then preferredthat some of the transmission lines are at least one conductor embeddedin an exterior cladding comprising at least one organic semiconductingmaterial, and that active regions are defined therein by contacting saidtransmission lines with other transmission lines of the same-kind orwith other transmission lines in intersection which comprises at leastone non-isolated or unclad conductor only, whereby semiconductingjunctions are formed at the contact points of said intersections. Inthis case it is preferred that the semiconducting junctions are formedspontaneously upon contacting, or that at least one of thesemiconducting junctions are a diode junction, or that the organicsemiconducting material is a semiconducting conjugated or non-conjugatedpolymer.

In the apparatus according to the invention it is advantageous that atleast some of the elements over some of their length are shieldedagainst any interactions in form of an exchange of energy between eachother or the exterior surroundings, whereas one or more unshieldedportions thereof are adapted for interactions of this kind, and it isthen preferred that the unshielded portions of the elements are locatedat the intersections thereof.

In yet another advantageous embodiment of the apparatus according to theinvention it is a two- or three-dimensional optoelectronic display andthe elements are then preferably signal transmission lines. Wherein thedisplay is a two-dimensional display are then the elements provided in atwo-dimensional array, preferably such that the elements intersect in asubstantially regular pattern or grid, said elements at theintersections thereof being adapted for absorbing or emitting electricalor optical energy. In this case a portion of at least one element in anintersection can be a pixel of the display.

Wherein the display is a three-dimensional display, it is according tothe invention preferred that the elements are provided with apredetermined pattern in a three-dimensional array, and then preferablythat the elements intersect in a spatially regular pattern or grid, saidelements in the intersections thereof being adapted for emitting orabsorbing electrical or optical energy. In this case is preferably aportion of at least one element in an intersection a pixel of thedisplay.

Wherein the display is a three-dimensional display with the activeregions of the elements provided in selected portions of the elementexposed in the surface of the fabric-like structure protruding therefromat selected locations thereof, it is preferred that the active regionsof this kind are pixels in the display, said active regions being eithera loop-like portion of an element or an end-point thereof.

Finally it is in the apparatus according to the invention advantageousthat it comprises respectively discrete electronic, optoelectronic oroptical devices or combinations thereof, and one or more discretedevices can then preferably be physical or chemical sensors connected toat least one of the elements.

In the apparatus according to the invention it can alternatively beadvantageous that one or more of the elements are a physical or chemicalsensor.

In the method according to the invention it is advantageous providingthe surface of the elements with a shielding or cladding material beforejoining into the fabric-like structure, and removing said shielding orcladding material after the joining into the fabric-like structure fromsome elements or from selected portions thereof at selected locations inthe fabric-like structure.

The invention shall now be described in more detail, with discussions ofexemplary non-limiting embodiments showinz various embodiments of thepresent invention and in conjunction with the appended drawings, wherein

FIG. 1 shows example of basic weaves such as the plain (a), the triaxial(b), the twill (c), the leno (d) and the satin (e) weaves,

FIG. 2 examples of knits such as the plain (a), the double (b), a warp(tricot) (c) knits and various weft knit stitches (d),

FIG. 3 examples of multicomponent fabrics such as the weft insertionwarp knit fabric (a), pile (b), carpet (c) and (d) fabrics;

FIGS. 4 a-e examples of possible shapes and compositions of the fibers,wires and ribbons composing the electronic or optoelectronic fabric,

FIG. 5 a simple loop detector woven into the fabric matrix,

FIG. 6 a detector using a pile of fibers as sensor,

FIG. 7 the integration of various functional units into the fabricmatrix,

FIGS. 8 a-c a display panel or a two-dimensional photo-detector,

FIGS. 9 a,b,c,d principles and embodiments of memory or switching arraysaccording to prior art and according to the present invention,

FIGS. 10 a-e dual-conductor structures of relevance as weavingfilaments, and

FIG. 11 an example of an apparatus realized as a flexible sheet-likestructure.

After a discussion of general aspects of the invention, examples ofembodiments shall be given.

As already stated, the given objects of the invention are specificallyrealized by weaving, knitting, crocheting, knotting and/or stitching acombination of conducting, semiconducting, superconducting and/orinsulating wires or fibers and/or optical fibers. These techniques, inthe following also termed joining processes, provide a high degree ofcontrol and constructive flexibility in creating integrated physicalstructures with electrical and/or optical functionality in two and threedimensions.

Control is in part related to the use of strands in the weaving,knitting, crocheting, knotting and/or stitching processes that arepre-made under precisely controllable conditions before beingincorporated into the final structure. Each strand can be made toinclude several different materials and sub-structures, e.g. in the formof electrical multiconductor cables, metallic filaments cladded withpolymers that engender electronic functionality when brought intocontact with other components in a woven structure, or optical fiberswith cladding for protection or environmental sensing.

Control is also a consequence of the degree of topographic order in 2and 3 dimensions that can be achieved by weaving, knitting, crocheting,knotting and/or stitching processes, where the identity and relativepositions of the strands are strictly defined according to apredetermined protocol.

Flexibility in creating 2- and 3-dimensional physical structures andachieving associated electronic and/or optical functionality springsfrom the diversity and sophistication that can be achieved by weaving,knitting, crocheting, knotting and/or stitching process, as demonstratedby the present state of the art within the textile industries. With theadvent of woven electronics, computer-aided design and manufacturingshall become important tools for creating new architectures andprocesses specifically targeting the needs and opportunities in thatfield.

Flexibility is also achieved by the absence of fundamental physical sizelimits: The strands in the weave may be as long as required for anygiven application and the ensuing circuit or apparatus may be scaled insize, in principle without limit. The form factor, i.e. size and shapeof the woven, apparatus may be chosen with few constraints, examplesinclude thin sheets as well as complex three-dimensional structures.Finally, circuits and apparatus according to the invention can beliterally, physically flexible when made in a wide range of embodiments.

A major aspect of the present invention is that it providesopportunities for creating integrated circuits of a radically new type,where electronic and/or optical functionality is embedded throughout thewoven, knitted, crocheted, knotted and/or stitched structures, with thestrands in the structures acting as signal and power conduits andcreating or promoting structural integrity. As shall be described indetailed examples below, the strands can provide many forms offunctionality, either at points where different strands come intophysical contact with each other and create junctions that exhibit e.g.luminescence, memory or switching behaviour, or in restricted regionswhere strands are exposed to external influences such as light, heat orchemical species, or distributed along portions of the length ofindividual strands, or at specific points where attachment has been madeto discrete functional components.

FIGS. 1, 2 and 3 examples of standard weaving and knitting patterns andcombinations thereof which are applicable, bur not exclusively, togenerate circuits and devices which then form an electronic oropto-electronic electronic fabric as used in the apparatus according tothe present invention.

The fibers, wires ribbons composing the circuits can have cross sectionsthat are round, oval, square, rectangular, polygonal or any otherdesired shape as shown in FIG. 4 a. They may be single-component ormulticomponent as shown in FIGS. 4 b-d. For purpose of clarity these areall referred to as fibers in the following text. The components ofmulticomponent fibers can be arranged in different ways depending on theneeds and applications. For instance a given fiber can be multicomponentin the cross-section and/or along the axis of the fiber, causing it toexhibit spatially varying physical, chemical and/or electricalproperties. The single-component fibers and different components inmulticomponent fibers may be either electrically conductive,semiconducting, superconductive, insulating, optically conductive or anycombination thereof, but are not limited to these. The components can beany sensor or detector material such as those activated by light, heat,chemicals, electric and magnetic fields. Individual fibers, singlecomponent or multicomponent ca be bundled or braided as shown in FIG. 4e.

The electronic or optoelectronic be composed of single component ormulticomponent fibers combined in various ways as exemplified by thepatterns in FIGS. 1, 2 and 3. The fabric can also be assembled frombundles or braided fibers, or from more complex filament-like structuressuch as electrical cables with multiple conductors separated bad adielectric. Fibers of different types and different dimensions can becombined in the fabric. For example, alternating conducting andinsulating fibers might be useful in some applications. The crossing oftwo or more fibers in the fabric are natural loci for devicefunctionality such as memory, switches, sensors, etc. The crossing canbe left as such or fused or bonded depending on the desired product.

There are no size limitations for these devices by the presentinvention. Individual devices can be created by weaving a given patternat a chosen position in the fabric matrix as illustrated in FIG. 5 for aloop detector and in FIG. 6 for a pile sensor. The inclusion of a pileof small sensor fibers in the matrix will yield a high surface areadetector, therefore high sensitivity. Such devices can be woven, knittedor stitched into the fabric matrix.

Such functional fabrics units and devices can be further combined bybeing woven or stitched or knitted into a larger fabric as illustratedin FIG. 7. Multilayers knitting is also possible if necessary. Theelectronic fabric can be finally impregnated with any substance such asan insulator.

The circuit or optoelectronics thus fabricated can be addressed from theedges of the fabric or anywhere in the matrix by weaving, knitting or n, stitching in connecting wires.

FIGS. 8 a-c shows a display device or two-dimensional photodetector inmatrix form as rendered in FIGS. 8 a,c. It is assembled by weaving twotypes of fibers as shown in FIGS. 8 a,b. One is a bi-component fiberwith a core consisting of, a conducting material M1 coated with anactive material A which for this embodiment is either anelectroluminescent material or a photoconductive material. The otherfiber is a conductor M2 M1 and M2 will typically have different workfunctions. Each crossing then becomes a pixel of the two-dimensionalarray, as in FIG. 8 c. For a colour display panel,the >electroluminescent material can be varied from one fiber to thenext. For instance, three successive fibers will correspond to the threecolours: red (R), green (G) and blue (B). Alternatively, differentvoltages can be used to generate different colors at each pixel. Thepixel density achieved by the invention will be much higher than thoseof prior art. The high density of pixels in such a fabric is ideal forhigh definition applications. FIG. 9 a shows a memory or a switchingarray, where specific addresses in the array are located in a crosspointmatrix fashion. i.e. by selectively activating the row and column thatcross at the point where the memory or switching cell is located.Variants of this basic scheme are employed extensively in theelectronics industry, often with semiconductor components embeddedwithin the matrix structure.

Typical embodiments of crosspoint matrices within the present state ofthe art are built on a silicon chip, where traditional lithographicsilicon technologies are used to create the conducting matrix gridlines,etc. According to the present invention, however, the rows and columnsin a matrix addressing system can be formed by wires crossing each otherin a weave. An example is given below.

A class of memory devices that are of particular interest in conjunctionwith novel thin film and organic electronic materials employ passivematrices, i.e. matrices where the functional cell at each crossing pointis very simple, without intra-cell transistor-based switching circuitry.One way of achieving addressability is to employ rectifying diodes toblock parasitic current paths between the two wires that cross at theselected cell, cf. FIG. 9 b. Such “sneak currents” are a well-knownproblem in passively addressed matrices, as is the remedy of insertingdiodes at the crossing points. Unfortunately, achieving this bytraditional semiconductor techniques (lithography, etching, doping,plating . . . ) is complicated and gives no competitive advantage overthe alternatives, which are the well-known active-matrix basedarchitectures used in ROMs, DRAMs, SRAMs, etc.

Recently, it has been shown, for instance in the International PatentApplication PCT/NO98/00185 which has been assigned to the presentapplicant, that very compact and simple matrices with diode-connectedcrossing points can be made by using conjugated polymers thatspontaneously create a diode junction when the polymer contacts a metalsurface. This opens up opportunities for passive matrix memory deviceswhere high-functionality organic and/or inorganic materials fill thevolume between the crossing matrix electrodes, performing memory andaddressability functions. A generic cell is shown in FIG. 9 c. Here, oneof the electrodes is contacting a material which forms a rectifyingjunction at the electrode/material interface, while the rest of the cellvolume is filled with a memory material which controls the electricalcharacteristics of the cell according to the logic state (e.g. storing alogic “0‘or ’1”). This memory material may simply be a masked insulatorin the ROM4 case, or it may be a material which can be switched betweena high and a low impedance state to form a WORM (Write Once Read Manytimes) or ERASABLE (write, erase, write . . . ) memory cell. Variants ofthe cell in FIG. 9 c include cells with only a single material whichsimultaneously takes care of the memory and addressability (e.g.:rectifying) functions.

In the prior art as illustrated in FIG. 9 c, the cells are formed bysandwiching the material in the cell (i.e. the memory and addressabilitylayers) between a set of bottom electrodes that are typically pre-formedon a planar substrate, and a set of top electrodes, which are typicallydeposited onto the material in the cell and patterned by additive orsubtractive processes. The simplest and most compact solutions areobtained when the materials in the cell are part of a layer that isapplied globally, without patterning. This, however, implies certaindrawbacks relating to restrictions on materials that can be used, aswell as the ultimate cell density achievable (lateral leak currents inthe cell materials).

In FIG. 9 d shows how a memory matrix with architecture equivalent tothe one shown in FIG. 9 c can be made with crossing wires that are wovensuch that a memory cell is formed spontaneously at each point wherewires in the weave cross. In the example shown, one set of wires extendin the x direction, the other set in the y direction. Each x wireconsists of a monofilament metal, cladded by a polymer which forms arectifying junction at the metal/polymer interface. Analogously, each ywire consists of a monofilament metal cladded by a substance whichexhibits memory properties. An intimate electrical connection is formedbetween the cladding materials at the crossing point by mechanical forceon the wires (pressure or stretching) during or after the weavingoperation, assisted by thermal or chemical means. The basic structure inFIG. 9 c can be refined in different ways, e.g. by insertingelectrically insulating separation filaments between the x and y wiresin the matrix. Advantages of this woven approach are several as itprovides a simple, virtually infinitely scalable means of creatingpassively addressed memory and switching matrices. Since the electrodes,memory and addressability materials are initially assembled asphysically separated modules, one largely avoids chemicalincompatibility problems which in alternative schemes severely restrictthe freedom of choice in materials and architectures.

With present invention a reduction of electrical interference andrelated noise mechanisms shall be possible by using dual- ormultiple-conductor structures as threads in the joining process.

In devices the size of present day chips and with the same wire densityand operating frequencies, the fabric-like architecture shall generallybe much more favourable with regards to electrical interference immunitysince the wires will be separated by air which minimizes the problem(low dielectric constant). See B. Shieh & al. “Air gaps lower k ofinterconnect dielectrics”, Solid State Technology, pp. 51-58 (February1999). In other large devices such as displays which operate atrelatively low frequencies, the woven architecture will also befavourable over existing technology.

However, devices that employ a very dense weave with mutually parallelor crossing filaments carrying signal currents at high frequenciesand/or over large areas are also of particular interest in the presentinvention. Important examples are device architectures where memorycells, logic circuitry, Cl fin amplifiers and interfacing electronicsare integrated in self-contained configurations on a common substrate.Clearly, crosstalk shall be a major problem if the interconnects arelaid out in close proximity to each other on the substrate without verycareful attention to capacitive and inductive pickup elimination.Several of the most potent strategies in this regard are difficult orimpossible to implement when traditional manufacturing technologies areused, e.g. a planar substrate with etched or deposited conductingstripes, typically in adjacent planar layers mutually separated byinsulating layers.

Weaving, knitting, crocheting, knotting and/or stitching techniquesprovide a unique opportunity to create devices where one needs tosuppress cross-talk g involving conductors that carry currents withinand to/from the apparatus, as well as achieving controlled signaltransmission properties in those conductors. Key to this is to employtwo- or multiple-conductor transmission lines with closely controlledgeometries that provide balanced current paths and shielding ofelectromagnetic fields. Such ultra-thin transmission lines could bemanufactured before being incorporated as filaments in the weave.

Examples of such structures are twisted wire pairs, coaxial and certaintypes of stripline conductors as discussed in more detail in thefollowing.

Using transmission lines with well-controlled electrical propertiesshall of course also present opportunities in addition to crosstalksuppression. An example is control of reflection properties at theterminations, of interest in high-speed circuits. Specific examples oftypes of transmission lines that can be embodied in the apparatusaccording to the invention are given below.

Example 1 Twisted pair filament conductors

See FIG. 10 a. The properties are well-known and extensively describedin the electronic literature. Good immunity against inductive pick-upfrom magnetic fields. See, e.g.: P. Horowitz and W. Hill: “The art ofelectronics”, pp. 456 et seq., Cambridge University Press, ISBN0-521-37095-7. Each twisted pair of conductors could be used as one ofthe threads in the weaving HI process. This thread would then be amonolithic structure, with the conductor pair maintained in the desiredpositions relative to each other by a rigid dielectric matrix material.

Example 2 Coaxial line conductors

See FIG. 10 b. Each coax line, with inner and outer conductors as wellas dielectric filling and coating materials, would constitute one of thethreads in the weaving process.

In general, for a lossless coaxial line having the radii r_(a) and r_(b)for the outside radius of the inner conductor and inside radius of theouter conductor, respectively, one has the following parameters.Capacitance per unit length: C=2πε/ln(r _(b) /r _(a))  (1)

-   -   (F/m)        Inductance per unit length: L=(μ/2π) ln(r _(b) /r _(a))  (2)    -   (H/m)        Characteristic impedance: Zo=(μ/ε)^(1/2)ln(r _(b) /r        _(a))/2π  (3)    -   (Ω)        Propagation constant: U=(πε)−1/2   (4)    -   (m/s)

Here, μ and ε are the dielectric constant (electric permittivity) andmagnetic permeability, respectively, of the fill material inside thecoaxial line.

A major issue is that the transmission lines must retain the electricalproperties of interest even as they are scaled down in size toultra-thin outer diameters. In that connection, one may note from theexpressions above that for lossless lines the characteristic impedancesand propagation constants L remain unchanged under linear scaling of thephysical dimensions. This naive approach is generally corroborated bymore realistic and thorough studies, under certain assumptions:

-   -   Thus, the small cross-sections of the center and outer        conductors imply that current paths must be short (typically a        few centimeters), in order to keep resistive impedance low. This        should present no problems in the present context.    -   Furthermore, the thin outer conductor provides poor shielding of        low frequency signals, highlighting the need for avoiding open        loops by precisely controlled symmetric conductor geometries and        uniform material properties in the line. The advantages in this        connection of pre-forming the coax line before incorporating it        into the substrate by weaving, instead of making such structures        in situ are self-evident.    -   Balanced current flows in the inner and outer conductors.    -   Operate at moderate to high frequencies (MHz to GHz).

Example 3 Flat conductor pair

See FIGS. 10 c-e, where 10 c shows a planar line, 10 d a strip line and10 c a symmetric strip line. Such transmission lines are high frequencysignal compatible and well-known in the literature, cf., e.g.: P.Horowitz and W. Hill: “The Art of electronics”, op. cit.

Example 4 Transmission lines in rolled-up devices

Novel devices of the generic type shown in FIG. 11 shall now bediscussed. Thin-film-based electronic and/or optoelectronic circuitryand components can as shown in FIG. 11 a be laid out on thin, flexiblesubstrates which may in principle be of any shape or size. Thus, thesize of the memory in data storage devices can be scaled by employing asubstrate of appropriate size. Very large area substrates in the form ofthin, is must be packaged into practical form factors. This can beachieved by stacking, folding or rolling (FIG. 11 b) together the thindevice-bearing substrates, whereby also high volumetric densities ensue.A recurring problem with such schemes is how to provide electricalconnections to all parts of the large areas involved. Thus, when thinsheets are stacked on top of each other, connecting wiring to each sheetor between sheets in a stack may represent an unacceptable cost orreduce technical performance.

The rolled-up scheme in FIG. 11 b is attractive in that signal and poweraccess can be established for a large-area, continuous structure, withonly a few external connections entering the reel at the end of therolled substrate. However, this solution implies that signal and powerlines may become very long, extending along the full length of therolled substrate. If traditional lithographic or printing technologiesare employed to create these signal and power lines, signal attenuationalong the length of the roll, reflections at signal branching andtapping points, and crosstalk between lines shall have a negative impacton technical performance, especially for high speed applications. Also,the creation of very long conducting lines by lithography or printingimplies vulnerability to defects at points along the conductor. Instead,the present invention teaches the use of transmission lines in the formof multicomponent, balanced structures, i.e. micro-cables or -wires thatcan be manufactured to consistent high quality in a separate productionstep prior to being incorporated into the rolled sheet. The latter canbe done in several ways, e.g.:

-   -   The transmission line can be stitched into a ribbon that        provides a uniform sheet-like substrate made from e.g. a        polymer.    -   The transmission line can constitute one of the strands in a        woven ribbon-like substrate which forms the rolled-up device.    -   A woven or braided length of multistranded material can be glued        or laminated onto a ribbon of flexible sheet substrate.

Since the transmission lines have well-defined characteristics, preciseimpedance matching can be used to tap the lines at separate points alongthe length of the rolled-up sheet without corrupting the signals.

The power and signal lines may be optical as well as electrical. In theoptical case, printing and lithography techniques are even lesscompetitive as compared to the use of fibers or cables, even over shortpropagation distances: Although optical waveguides deposited or etchedon planar A substrates are well-known, e.g. as optical circuit elements,typical propagation distances are of the order of centimeters. Opticalfibers, on the other hand, are widely used in signal transmission overthousands of kilometers.

The filament diameters of relevance in woven electronics applicationsshall typically be small, i.e. <100 microns. There exists a large bodyof knowledge within the general field of joining processes, etc, derivedfrom the textile industry, and this encompasses technologies forhandling ultra-thin filaments. In the present context, however, certainnew elements are introduced. i.e. the requirement that at least some ofthe individual filaments shall possess explicit electrical and opticaltransmission properties. This shall not necessarily imply any majordeparture from traditional weaving technologies as long as monofilamentsof metals or optical glasses or plastics are concerned. However, dual-or multiple-conductor filaments represent a novel aspect, both asregards the manufacture of the conductor structures themselves and theirincorporation into woven devices.

Coaxial lines are of particular interest in the present context.Micro-coaxial cables are extensively used in low power level, highfrequency applications, e.g. radar signal conditioning. To ourknowledge, the thinnest commercially available cables are approximately0.5 mm. in outer diameter, i.e. too coarse for fabric-like or wovenelectronics applications. On the other hand, there is no principalreason why much thinner coaxial cables could not be made. Indeed, thereis presently being conducted research on nanoscaled electronic deviceswhich also includes ultraminiature electrically conducting wires andsheathed cable, cf.: Y. Zhang et al.: “Coaxial nanocable: SiliconCarbide and Silicon Oxide Sheathed with Boron Nitride and Carbon”,Science, Vol.281, pp. 973-975 (Aug. 14, 1998).

Below the connection to specific conductors at selected locations insidethe weave shall be considered in more detail.

In the fabric-like or woven electronics concept, there is a need tocouple selected conductors in the weave electrically to components andother conductors, at well-defined points in the weave. This task isnon-trivial in cases with a highly dense weave consisting of ultra-thin,possibly coated conductors running all the way from the edge of theweave. Some basic principles that can be followed:

-   -   Insert locally a wire which is just stripped at the tip to make        electrical contact while the rest of the wire is coated with an        insulator. The inserting of fibers or filaments locally is a        common fabric technology.    -   Insert an optical fiber or fiber bundle to send signals to and        from a photodetector/emitter.    -   Post-insertion stripping or other treatment of localized areas        on fibers, wires and filaments to gain access to the signal or        power paths can be performed in a number of ways. For example,        using openings in a Eg patterned mask lithographically defined        directly on the weave or through a membrane in proximity,        selected portions of the electrically insulating material        surrounding conducting wires can be removed by etching or they        can be modified by doping.

Alternatively, one may employ a beam which writes the positions whereconductors are to be exposed, either by direct erosion (ion beam) orindirectly via a sensitizing beam.

In many cases, it is useful to separate conducting leads in the weavefrom each other by inserting intermediate insulating strands in the web.This simplifies the task of avoiding unintentional stripping of thecoating layer on conductors close to the one to be connected. Anotherway of avoiding contact with near-lying strands is to employ coatedconductors with different dissolution properties for the coatings, cf.the specific following examples.

Example 5

In a line of the “twisted pair” type consisting of two metal filamentswith insulated coatings applied on each separately before being twistedtogether: b) There are two types of coating, one for the “hot”, one forthe “cold” filament, where the solubilities of the coatings in specificchemicals are different. The metal core in the “hot” filament w,couldthen be laid bare at a given location by selectively dissolving thecoating on that filament using a chemical etchant which only attacks thehot” filament coating. The extent of the dissolution region could becontrolled by exposure to the chemical etchant through alithographically defined opening in a protective film.

Example 6

A variant of Example 1 is localized selective sensitization followed byE chemical etching: The “hot” filament coating would be made soluble toa given reagent in desired locations, by exposure to the sensitizingagent (vapor, liquid, light, heat, particle beam . . . ) through alithographically defined opening in a protective film.

Example 7

The same basic principles as in Examples 5 and 6 can be employed withother types of selective stripping methods than chemical dissolution.Such methods include dry etching by photon (e.g. eximer laser) orparticle irradiation, exploiting differences in etching rates of thecoatings. The latter may be linked to, e.g. different hardness of thecoating materials or to differences with respect to absorption of theirradiating photons or particles, or differences in etching rates

Example 8

Instead of using lithography to define the areas that shall be subjectedto etching, one may use inkjet printing to either deposit the protectivelayer or the etching agent itself.

Example 9

Instead of using lithography to define the areas that shall be subjectedto etching, one may use vector or raster scanning of a light or particlebeam to achieve localized etching or sensitization. This way, severalproduction steps can be avoided. *The advantages of the presentinvention are several. Electronic and optoelectronic functionality canbe achieved on a wide scale of complexity and degree of integration inscalable two- or three-dimensional structures that are physically robustand flexible with respect to form factor. Integration of both opticaland electronic circuits is simplified since material compatibility isnot an important issue. Yet another advantage of the invention is theflexibility in the circuit design which can be continuously changed andadapted to meet specific needs. Wires can be looped and structured insuch a way as create functional devices at any point or area in thewoven matrices.

The invention also provides a simple way to produce defect-tolerantarchitecture. See Heath & al. op. cit.

With the present invention a whole new class of electronics and/oroptoelectronic apparatus will be possible. Particularly the inventionoffers the possibility of initially large-area flat devices which may bemade as flexible fabric-like or woven structures and thus easily beform-adapted for specific purposes, in addition to being area-scalable.Such devices shall be well-suited for creating novel display devices andmay as desired be made to be integrated with active and/or passive knownelectronic, optoelectronic or optical devices.

1. A web of circuitry comprising: at least two circuit elements, eachhaving ends; at least one physical intersection of said elements, wherethe intersection does not occur at the ends of said elements; and apredetermined circuit pattern, wherein said elements are arranged inmultiple-dimensions according to said pattern, where the intersection isa point of communication between elements, where the intersections andvarying properties of the elements form active regions, where the activeregions are associated with circuitry in the pattern, where at least oneelement is a transmission line or an isolator and wherein said elementsare arranged in said predetermined circuit pattern by integrating saidelements using weaving, knitting, crocheting, knotting, or stitching. 2.The apparatus according to claim 1, wherein the pattern is atwo-dimensional fabric-like structure.
 3. The apparatus according toclaim 1, wherein the pattern is a three-dimensional fabric-likestructure.
 4. The apparatus according to claim 1, wherein the elementsare arranged such that the positions of the ends of the elements definea spatial grid.
 5. The apparatus according to claim 1, wherein someelements are twisted pair transmission lines.
 6. The apparatus accordingto claim 1, wherein some elements are transmission lines that arecoaxial cables.
 7. The apparatus according to claim 1, wherein someelements are stripline transmission lines.
 8. The apparatus according toclaim 1, wherein some elements are optical fibre transmission lines. 9.The apparatus according to claim 1, wherein the elements have activeregions that are defined by exposing portions of the elements to theencompassing environment.
 10. The apparatus according to claim 1,wherein said element has an active region that is extended lengthwisetherein.
 11. The apparatus according to claim 1, wherein said elementhas an active region that corresponds to an end thereof.
 12. Theapparatus according to claim 1, wherein some of the elements areprovided with a protective shielding or cladding, the active regions inthese elements being provided by removing the shielding or cladding atselected portions thereof.
 13. The apparatus according to claim 1,wherein the active regions of the elements are provided in selectedportions of the elements exposed in the surface of the fabric-likestructure or protruding therefrom at selected locations thereof.
 14. Theapparatus according to claim 1, wherein the active regions of theelements are defined by exposing portions thereof to spatially selectivephysical or chemical influences.
 15. The apparatus according to claim14, having at least two transmission lines wherein at least onetransmission line is a conductor embedded in an exterior claddingcomposed of an organic semiconducting material, where active regions aredefined by contact between transmission lines, and where semiconductingjunctions are formed at the contact points of said intersections. 16.The apparatus according to claim 15, wherein the semiconductingjunctions are formed spontaneously upon contact.
 17. The apparatusaccording to claim 15, wherein at least one semiconducting junction is adiode junction.
 18. The apparatus according to claim 15, wherein theorganic semiconducting material is a semiconducting polymer.
 19. Theapparatus according to claim 1, wherein some of the elements, havingcharacteristic lengths, are shielded over a portion of the lengthsagainst exchange of energy between elements or the exteriorsurroundings, where one or more unshielded portions are adapted toenable exchange of energy through the unshielded portions.
 20. Theapparatus according to claim 19, wherein the unshielded portions of theelements are located at the intersections thereof.
 21. The apparatusaccording to claim 19, wherein the apparatus is a two- orthree-dimensional optoelectronic display where the unshielded portionsemit light at predetermined intensities, frequencies, and locations. 22.The apparatus according to claim 21, wherein at least one of theelements is a signal transmission line that carries the predeterminedintensities and frequencies to predetermined locations in the pattern.23. The apparatus according to claim 22, wherein the display is atwo-dimensional display, wherein the elements form a two-dimensionalarray of equally spaced elements.
 24. The apparatus according to claim23, wherein the intersections are adapted for absorption or emission ofelectrical or optical energy.
 25. The apparatus according to claim 24,wherein a portion of at least one element in an intersection is a pixelof the display.
 26. The apparatus according to claim 22, wherein thedisplay is a three-dimensional display, wherein the elements areprovided in a three-dimensional array of equally spaced elements. 27.The apparatus according to claim 26, wherein the elements intersect in aspatial regular pattern or grid, where some elements in the pattern areadapted for emitting or absorbing electrical or optical energy.
 28. Theapparatus according to claim 26, wherein a portion of at least oneelement in an intersection is a pixel of the display.
 29. The apparatusaccording to claim 26, wherein active regions of the elements areprovided in selected portions of the element exposed in the surface ofthe fabric-like structure or protruding therefrom at selected locationsthereof, where the active regions are pixels in the display, said activeregions being either a loop-like portion of an element or an end. 30.The apparatus according to claim 35, wherein the pattern containselements that are discrete electronic, optoelectronic or optical devicesor combinations thereof.
 31. The apparatus according to claim 30,wherein one or more of the discrete devices are physical or chemicalsensors connected to at least one of the elements.
 32. The apparatusaccording to claim 35, wherein one or more of the elements are aphysical or chemical sensors.
 33. The apparatus of claim 1, wherein atleast one intersection and associated elements form an active regionwhere the physical properties of the elements result in the absorptionor emission of energy in the region.
 34. The apparatus of claim 33,wherein the intersection absorbs electrical or optical energy.
 35. Theapparatus of claim 33, wherein the intersection absorbs chemical ormechanical energy.
 36. The apparatus of claim 1, wherein at least oneintersection allows electronic communication between the elementsassociated with the intersection.
 37. The apparatus of claim 1, whereinone element is composed of a transparent material.
 38. The apparatus ofclaim 1, wherein one element is composed of a conducting material. 39.The apparatus of claim 1, wherein one element is composed of asemi-conducting material.